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New roles in space for the 21st century: a Uruguayan view 总被引:1,自引:0,他引:1
In the economic and social circumstances of the 21st century globalized world, there is a need to rethink the traditional roles and positions in space of international intergovernmental organizations, states, both developed and developing, and humankind itself. Uruguay provides an example of a non-typical country that has managed to carve an important niche for itself in the field of space law. Although globalization is an irreversible phenomenon, which has had a devastating effect on the weakest countries, following the attacks of 11 September 2001 insecurity has become globalized for everyone. From the point of view of a state such as Uruguay, this crisis must be looked upon as an opportunity to renew and inspire intelligence, education and culture. In this way—and by continuing to argue for a global space organization—it can contribute to making the Space Age an era of global and planetary solidarity for the benefit of humankind. 相似文献
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The problem of spinning-up an axially symmetric spacecraft subjected to an external torque constant in magnitude and parallel to the symmetry axis is considered. The existing exact analytic solution for an axially symmetric body is applied for the first time to this problem. The proposed solution is valid for any initial conditions of attitude and angular velocity and for any length of time and rotation amplitude. Furthermore, the proposed solution can be numerically evaluated up to any desired level of accuracy. Numerical experiments and comparison with an existing approximated solution and with the integration of the equations of motion are reported in the paper. Finally, a new approximated solution obtained from the exact one is introduced in this paper. 相似文献
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《Space Policy》2014,30(3):163-169
The planning of human spaceflight programmes is an exercise in careful rationing of a scarce and expensive resource. Current NASA plans are to develop the new capability for human-rated launch into space to replace the Space Transportation System (STS), more commonly known as the Space Shuttle, combined with a heavy lift capability, and followed by an eventual Mars mission. As an intermediate step towards Mars, NASA proposes to venture beyond Low Earth Orbit to cis-lunar space to visit a small asteroid which will be captured and moved to lunar orbit by a separate robotic mission. The rationale for this and how to garner support from the scientific community for such an asteroid mission are discussed. Key points that emerge are that a programme usually has greater legitimacy when it emerges from public debate, mostly via a Presidential Commission, a report by the National Research Council or a Decadal Review of science goals etc. Also, human spaceflight missions need to have support from a wide range of interested communities. Accordingly, an outline scientific case for a human visit to an asteroid is made. Further, it is argued here that the scientific interest in an asteroid mission needs to be included early in the planning stages, so that the appropriate capabilities (here the need for drilling cores and carrying equipment to, and returning samples from, the asteroid) can be included. 相似文献
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Life support components are evaluated for application to an idealized closed life support system which includes an algal reactor for food production. Weight-based trade studies are reported as "break-even" time for replacing food stores with a regenerative bioreactor. It is concluded that closure of the life support gases (oxygen recovery) depends on the carbon dioxide reduction chemistry and that an algae-based food production can provide an attractive alternative to re-supply for longer duration missions. 相似文献
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税后薪资标准的出现,不仅仅是一种薪资形式上的改变,而且对于劳资双方来说,这一变化有着不同的意义。首先,对于劳动力市场来说,由于大多数企业仍采用传统的含税薪资,如何将税后薪资换算为传统的含税薪资,从而将两者加以比较,便成了应聘人员普遍关心的问题。而另一方面,企业实行税后薪资,必然涉及到代付个人所得税问题,这又直接关系到企业的税务筹划问题。 相似文献
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At present we have only one agreed public policy for handling the detection of an extraterrestrial intelligence (ETI), the ‘First SETI Protocol’ of 1989, which guides action in the immediate aftermath of detection, even though SETI (the Search for Extraterrestrial Intelligence) constitutes an active search for such a detection. The purpose of this paper is to set out areas in which policies might fruitfully be developed, including reviewing the rationale and investment in SETI, handling ETI artefacts, and approaches to direct contact. ‘Negative’ possibilities will be examined, for example, whether an ETI artefact or data should be purposefully destroyed. 相似文献
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Inter-Satellite Link represents an innovative aspect in remote sensing missions, allowing the exchange of data between satellites of a constellation according to appropriate algorithms for the minimization of the delivery time of requested data. In a recent study, the feasibility of gaining a long period of Inter-Satellite Link with an acceptable level of Bit Error Rate has been demonstrated by using a Walker Constellation composed of 20 micro-satellites located on Sun-Synchronous Orbits. In this paper, an investigation into the performance of such a constellation through the implementation of an optimal process of target access and data exchange among satellites has been carried out, together with a sizing of the onboard telecommunication system. A process analysis has been executed through the modelling of weighted fitting functions, specific for an optical remote sensing system. 相似文献
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This paper aims to present a set of lost-in-space star identification algorithms that works effectively for small satellites. Several algorithms are investigated for both phases of star identification: feature extraction and catalogue search. For feature extraction, it is shown that an algorithm using extended images with combined images works best, and for catalogue search, the Group Catalogue is shown to be most efficient. Therefore, this paper proposes an algorithm combining these three. Simulation results show the effectiveness of this algorithm for its robustness to various errors, and an application of this algorithm, “unequal” star trackers, is introduced. 相似文献
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A major problem with operations of lifting reentry vehicle having an aft center-of-gravity location due to large engine mass at the rear is the required hypersonic trim to fight the desired trajectory. This condition is most severe for lifting maneuvers. As a first step toward analyzing this problem, this paper considers the lift requirement for some basic maneuvers in the plane of a great circle. Considerations are given to optimal lift control for achieving the maximization of either the final altitude, speed or range. For the maximum-range problem, phugoid oscillation along an optimal trajectory is less severe as compared to a glide with maximum lift-to-drag ratio. An explicit formula for the number of oscillations for an entry from orbital speed is proposed. 相似文献
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河北省计算机一级考试是面向省内普通高校在校学生的计算机等级考试,是用人单位进行计算机操作水平认定的重要标准,在高校中备受重视。本论文首先分析了河北省计算机一级考试的特点,然后总结分析了2006-2008年度考试操作题的考点分布及变化趋势。最后提出了正确备考的建议和策略。 相似文献
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Bhupendra Jasani 《Space Policy》1985,1(4):363-368
Dr Jasani argues the urgent case for establishing an international satellite monitoring agency, with an arms control and conflict observation satellite (ACCOS). He gives examples of recent technology advances and cites the imminent major development of space weapons by the USA and the USSR as a pressing reason for setting up a verification and crisis control mechanism. Both Europe and the non-aligned nations are in a position to participate in orbiting an ACCOS. 相似文献
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空间原子氧环境是低地球轨道空间环境的重要组成之一,未来的原子氧探测技术要求探测载荷不仅在重量和功耗方面比现有技术大幅降低,而且在探测性能上要有极大的提升,特别是能实现原子氧通量的实时探测。文章在分析目前主要原子氧探测类型及其特点的基础上,提出一种基于碳纳米管气体传感器的原子氧探测技术。其探测仪器具有体积小、功耗低、灵敏度高、可实时探测、能长期连续工作、可重复使用等特点,是纳米传感器技术发展的重要方向。该技术一旦成功应用,有望快速提高我国在原子氧探测方面的技术水平。 相似文献
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指出目标运动先验信息、系统结构信息和设备测量信息的融合应用是提高滤波器跟踪性能的核心。进而综述了弹道目标融合滤波中的运动模型构造、滤波算法设计以及测量误差处理等环节中的关键技术和研究现状。并针对传统实时处理结构弊端,分析了实时跟踪系统的设计方法,讨论了如何建立高效的弹道跟踪数据处理流程,通过融合策略并举的方式实现系统各类信息的有效利用。一些设计方法可以为实际跟踪滤波器的开发提供参考。最后,结合空间应用的发展需求,分析了弹道目标跟踪技术的研究方向。 相似文献
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In 2012 a working group was established to formulate the African space policy and strategy which would lead to the establishment of an African Space Agency (ASA). Dr Peter Martinez asserts in his article “Is there a need for an African Space Agency?” [1] that the arguments that have been posited in support of an ASA are flawed; namely the arguments of the existing example of the European Space Agency (ESA), and that an ASA would lead to fostering competition, synergy, industrial development and capacity building. While this viewpoint agrees that all the perfect conditions may not exist at present for the creation of an ASA, it addresses some of the issues raised by Martinez, and proposes ideas to foster intra-regional cooperation. 相似文献
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空间天气科学与有效和平利用空间 总被引:2,自引:2,他引:0
空间天气科学是一门新兴的前沿交叉科学。文章首先从发展历程、发展现状和发展态势角度对空间天气科学进行了系统介绍,并指出空间天气科学是经济社会发展的"助推器"、助力科技革命的"加速器"和关系空间安全的"倍增器";接着对空间天气科学与有效和平利用空间的关系进行了阐述;最后对我国空间天气科学的发展和对人类的服务前景进行了展望,并给出了制定和实施"国家空间天气十年计划"和"空间天气科学服务和平利用空间国家专项"建议的初步构想。 相似文献